The RE272 are very good sounding IEMs with wider soundstage, crisp clear mids, highs and good bass response, overall they are very balanced yet musical and detailed. The other IEMs like Sony EX1000, ER4P, UE900, Heir Audio 4Ai and CK10 are very balanced and highly detailed without being bassy...

The Sony MDR-R1, Sennheiser Momentium, Denon D600, Klipsch Reference M40 and Pro900 are highly recommmended, they all have different soundsignatures but overall soundquality is very good and they are comfy to wear for long sessions.

IMO TDK-BA200 are supperior sounding IEMs with good bass response, great midrange, clear highs and wide open soundstage.

The Klipsch Image ONE, Sony XB800 are great buy under this budget and they offers crsip clar soundquality with pwerful bass. If you can find V-Moda M80(USED) and they are amazing sounding(deep rich bass, crsip clear mids, highs, fairly wide soundstage).

The UE TF10Pro(used), UE SF5Pro are amazing for that price and has everything you are looking for in the IEMs.

The Sennheiser Momentium, Denon D600(with AMPs help sound even bigger and better) and V-Moda M80 are pretty good sounding for the price and they match well with above list.

If you want bassy and crisp clear soundquality then Denon D2000 are very good sounding eadphones, Sennheiser Amperior,Vmoda M80 are also great buy.

The X10, SE215, JVC FXD80, Yamaha EPH100, UETF10Pro are very good sounding budget IEMs but if need very balanced soundquality then RE0, HF5 are better buy.

The IEMs with good isolation, crisp clear sundquality are like ER4P/S, CK10, EQ7.

The Portapro are already very good sounding pair and if add AMPs/DAC in chain then they will realy improve and i will recommend these AMPs/DAC iBasso D7, ODAC/O2 AMPs, E17 and XM6. You can buy highend IEMs later for more portability, isolation, better soundquality and AMPs/DAC will help them for...

I think Etymotic ER4P/S with AMPs willbe better than any westone IEMs if need higher resolution soundquality.

The CK10, R-50, DBA-02 and B2 are very close to ER4S and they shows all hidden details in mids, highs with better bass response.

The Ie800 price is much higher than Shure SE535 RED (Asia) but both are very good sounding and IE800 are supperior in term of soundquality due to better soundstaging, iamging and separation.

The UM3x are great with guitar based music and they are very detailed with good punchy bass and superb imaging.. Others IEMs like UE900, Sony EX1000, PFE232 and ATH_CK100Pro are also good match for guitars sounding good on these IEMs.

The RE0, RE-ZERO are very good with classical genres music because locational cues are great on these with good imaging,instruments position within the soundfield and very detailed mids, highs and bass response(highly recommended, they improve further with AMPs help). Others like Sony EX600, JVC...